moseley r



F. L. MOSELEY AIRCRAFT FLIGHT INDICATOR AND CONTROL SYSTEM THEREFOR Dec. 25,1945.

Original Filed Sept. 17, 1936 V 4 Sheets-Sheet 1 11v Vzv'rok I Fflmvcls 'LMOSELEY BY x 1945- F. L. MOSELEY Re. 22,704

AIRCRAFT FLIGHT INDICATOR AND CONTROL SYSTEM THEREFOR I Original Filed Sept. 17, 1936 4 Shuts-Sheet 2 IN VE 1V T 01? .NoazsLsY Dec. 25, .1945. F. L. MOSELEY AIRCRAFT FLIGHT INDICATOR AND CONTROL SYSTEM THEREFOR Original Filed Sept. 17, 1936 4 Sheets-Sheet 3 66 a 52' L N 54 3| 34' .29 56 37 WWI '21 *IIII HHHHH ||.|1|.|.l.|.|.| mi 3 0 1- O i Q #15 4 142 15a o 3! 5 0 I .i m

Li a I39 if; 5. .94 I II LIP-r; A

1N VEN T 0/? fim/vc/s L. Mos ELEY JAM/X 7 H'I-S ATTOR 5y F. LQMOSELEY V Re.'22,704

AIRCRAFT FLIGHT INDICATQR AND CONTROL SYSTEM THEREFOR Original Filed Sept. 17, 1936 4 Sheets-Sheet 4 To Lmvnme BEAM Rec. To Gaum BEAM fisc.

DIRGYIO 1N VENTOR HAS ATTORN Y.

Reissued Dec. 25, 1945 AIRCRAFT. FLIGHT INDICATOR AND CONTROL SYSTEM THEREFOR Francis L. Moseley, Osborn,-

S erry Gyroscope Company, Inc.,

Ohio, assignor to Brooklyn,

N. Y., a corporation of New York Original No. 2,262,033, dated November 11, 1941,

Serial No. 101,274, September 17,1936.

plication for reissue December 14, 343, Serial 42 Claims.

This invention relates; generally, to aircraft instruments and the invention has reference, more particularly, to a novel aircraft flight indicator that conveniently and clearly indicates on its face flight information heretofore shown on the faces of a plurality of separated instruments.

The gradual increase in the accuracy and number of aircraft instruments over a period of years has greatly improved the art of flying until today blind flying, or flying entirely by instruments, is an accomplished fact. However, great difficulty is experienced by pilots in trying to simultaneously observe and intelligently follow the indications of a number of important instruments while maneuvering their craft at the same time in response to the various indications of such instruments, and this is particularly true when making blind landings. While watching one instrument, the pilot fails to see changes in the indications of other instruments, with the result I that proper maneuvering of his craft is almost impossible, especially when landing as when following a radio landing beam or beams.

The principal object of the present invention is to provide a novel aircraft flight indicator and control system therefor that operates to clearly indicate on a single instrument face all of the immediate flight information needed by the pilot while flying, whether during normal flight, or while following a directional radio beam, or while landing as by means of radio beams, directional beam and a radio landing beam.

Another object of the present inventionlies in the provision of a novel flight indicator and control system therefor of the above character that is so constructed and arranged as to present flight information by indications that simulate, as far as practicable, the actual attitude or orientation of the craft with respect to a reference point or points, for example, the horizon and the meridian, in such a manner that the indications may be readily understood and interpreted by reason of their distinctiveness and coordinated movement.

Still another object of the present invention is to provide a novel flight indicator and control system of the above character wherein a cathode ray tube is employed for giving the desired indications, suitable control potentials being supplied from electrical pick-off devices provided on the various conventional instruments whose indications are to be given by the instrument of the present invention, means being provided for applying the same in sequence by means of a commutating device to the cathode ray tube, thereby preventing any interference between said potentials; the design of said'electrical'pick-off devices and the manner of applying said control potentials to the cathode ray tube being such as to produce the desired types of indications and changes of indications on of said cathode ray tube. t

A further object of the resent invention lies in the provision of a novel aircraft flight indicator of the above character that is adapted to be mounted on the instrument board of an air'eraft, thereby enabling a plurality of instruments to be removed from such board, if desired, thereby greatly simplifying the board, said instruments being installed in any convenient locationon the craft, electric leads extending from such instruments to the flight indicator of this invention serving to convey the indications of such instruments to the flight indicator for reproduction by the latter. 7

Still another object of the present invention is to provide a novel aircraft flight indicator and control system therefor of the above character that is so constructed and arranged as to enable duplicate indicators or repeaters to be operated therefrom, said repeaters being located at any desired point or points of the craft.

Other objects and advantages will become apparent from the specification, taken in connec tion with the accompanying drawings wherein the invention is embodied in-concrete form.

In the drawings,

Fig. 1 isa schematic view illustrating the novel flight indicator of this invention, including typical connections of other instruments to the same.

Fig. 2 is a wiring diagram of the flight indicator and control system therefor, the said diagram illustrating the use of electromagnetic pick-off means from certain instruments.

Fig. 3 is a. vertical, part sectional view of a directional gyro provided with an electromagnetic pick-off that may be employed,- and also showing remote controlled caging and setting means for the gyro. I V

Fig. 4 is a vertical, part sectional view of an artificial or gyro-horizon provided with an electromagnetic pick-cu.

Fig. 5 is a vertical, part sectional view of a turn indicator provided with an electromagnetic pickofi',

Figs, 6, 7 and 8 are schematic views of the face of the flight indicator, showing the indications of the instrument under varying conditions of flight. v

Fig. 9 is a wiring diagram of the flight indicathe fluorescent screen 2 r tor and somewhat modified control system therefor, the said diagram illustrating the use of capacity pick-off means from certain instruments.

Similar characters of reference are used in all of the above figures to indicate corresponding parts.

Referring now to Fig. 1 of the drawings, the

reference numeral l designates the novel air,-

craft flight indicator of this invention, which indicator is adapted to be mounted on the pilots instrument board or at any other convenient location in the aircraft. The indicator I comprises a front panel 2 provided with a circular aperture for accommodating the sensitized end or face of a cathode ray tube or oscillograph 3. The face of tube 3 is provided with annularly disposed indications 4 corresponding to degree or compass markings for use in conjunction with the cathode beam spot I in determining the bearing or course of the aligned horizontal lines 5 and 5' marked on the tube face indicatethe transverse axis of the air- .craft and are used in conjunction with a transverse cathode beam line or artificial horizon line "8 for indicating pitch and roll of the craft, where- "as vertically extending markings 6 and 6' are used in conjunction with a vertical cathode beam line 3 in indicating turns of the craft. The center of the circular tube face is provided with an opaque o black spot around which extends a circular cathode beam line II that cooperates with spot III in indicating whether or not the craft is properly on a radio course or landing beam, or both. A cathode beam intensity knob 13 and a focussing knob l4 are provided on the lower half of panel 2. A switch l for controlling the caging and setting of the directional gyroscope and an off and on switch I6 are also provided ion panel 2. I

The indicator'l is connected by an electrical cable l1, containing a number of leads, to'a detecting,'amplifying and commutating apparatus 18 thatmay be located at any convenient place "on the craft and preferably adjacent the instruments whose indications are to be portrayed by the indicator ofthis invention. A branch cable I1 is illustrated as extending from cable I! for the purpose of controlling additional or repeater indicators (not shown) similar to indi- 'cator' land located in other parts of the craft,

should such additional indicators be desired. The apparatus I8 is connected by suitable cables or leads, as shown, to the various conventional rate and attitude instruments (see Instrument *Flyin'g, by Howard C. Stark) Whose indications 'are'to be consolidated and portrayed by the in-, dicator I., These instruments are shown as including a turn indicator I 3, a directional gyro or compass 20, a gyro or. artificial horizon 2|, a radio course beam receiver 22, a radio landing 'beam receive 23 and an air speed indicator 24. Although these instruments are shown in the drawings as they might appear upon the pilot's instrument board, it is to. be understood that the same need not be mounted upon the instrument board, thereby greatly simplifying the latter, but may be conveniently installed in a box or cabinet at any suitable point of the craft and, further,- since the indications of these instruments are to be portrayed by indicator I, these instru ments may be skeletonized, if desired, i. e., all non-essential parts of the instruments may be pmitted, including their indicating faces and operating pointers or members, thereby reducing the cost thereof. I I

craft. Short, heavy,

In the wiring diagram of Fig. 2, leads 25 supply single phase A. C. to a transformer or transformer means 26 having a plurality of secondary windings. One secondary winding of transformer 26 supplies current through leads 2'! to the pick-off energizing coils 28,, 29-and 30 ofpick-off devices or means associated with the directional gyro. the gyro horizon and the turn indicator, respectively. These instruments together with their pick-off devices or means are respectively shown in Figs. 3, 4 and 5. The coil 28 (see also Fig. 3) is mounted on the central pole of a five pole core 3| having the remaining four poles distributed at right angles to one another about the central pole. Thecore 3| is carried by the directional gyro housing 38 and the central pole of this core carries the upper bearing pivot pin 31. of the vertical gimbal ring 33 concentrically therewith.

One pair of diametrically opposite poles of core 3| is provided with coils 32 and 32' that are connected in series with one another and with the primary winding of an input transformer 33. Similarly, the remaining pair of diametrically opposite poles is provided with coils 34 and 34 that are connected in series with one another and with the primary winding of an input transformer 35.

A circular disc 35 of magnetically conducting material such as soft iron is fixed on top of vertical ring 39 somewhat eccentrically to the pivot pin 31 and is positioned just under the poles of core 3!. Due to the eccentric mounting of disc 36, the magnetic coupling provided thereby between the energized coil 28 and the respective outer coils 32, 32', 34, 34 varies as the casing 38 turns with respect to the vertical ring 39.1. e., as the course of the craft changes, and

hence the voltage outputs of 32, 32' and 34, 34' varies as the course changes so that the voltage inputs to the transformers 33 and 35 correspondingly varies.

The secondaries of transformers 33 and 35 are connected to the grids of thermionic means disclosed as comprising detector-amplifier or balanced modulator tubes 40 and 4|. Each of these tubes produces in its output a direct current voltage of magnitude and polarity determined by the magnitude and phase of the input A. C. supplied to its respective input transformer. These two direct current outputs are connected through synchronously driven arms and of commutators 42 and 43 to the vertical and horizontal deflecting plates 44, 44' and 45, 45' of the oscillograph 3, so that for any position of the directional gyro a spot 1 (Fig. 1) is produced near the periphery of the face of tube 3 in the proper position to indicate the crafts course on the scale 4.

Thus, when relative movement takes place between the directional gyro and the craft, the magnetic coupling between coil 28 and coils 32, 32' is altered and the voltage generated in the latter coils is fed through input transformer 33 and the grids of double triode tube 40 in push pull to equal resistors 46 and 46'. An A. C. plate voltage is supplied from one terminal of a secondary Winding of transformer 26 through 'a lead 41 to the point of connection of resistors 46 and 43' and through these resistors to the plates of tube 40, the other secondary winding terminal being connected through another lead '41 to the tube cathodes.

' When the signal voltage from coils 32 and 32 is zero, the D. C. voltage drops across resistors 46 and 45 are equaland opposite and the D. C. voltthe pairs of coils ""ze'be 'enthe outer termmais ia and ta'er I ese 1- sisters r0. liowevenwhen'thesignal liloltiigejffdmjcoil nd 32'flS other than item, the "utputsof theplates of tube m ar'e no longer droneof the tubeplate' circuits havl'n'ge arge ,btifre'ntbutriut than the other depniii'ng :upon e dire'ction-of turningof disc -36,*so that the voltages across resistors 16 "and 46 are no 'fl nfgerfedual and a "net l3. C. vbltaige appears attioss points 48 and '48. condenser -"5'I- srnoths outthis net D. C. voltage. P 0int=48-i's"con'nected 35d. 190 "se ment "A of 1 commutator 42; conjt'a'ct' a 50ther'ebffand lead 5l'tothe upper'v'e'rftica deflecting plate 44, whereas point 48 is {connected by- 1ea'ds 52 and"53to the lower vertical defiecting plate 44. Thus, "the voltage "across '48'and'WB appears across -=verti ca1 deflect- '-pl'ate's 4'4 and '14. Resistance "5B is a-"g'rid deal; resistor common to both grids of tube'fl'll. V a -Siiriilarly, "a voltage "appearing across coils 34 ii'd 4' is fed to-transform'r-fi, thatapplies the met'o th'e' grids'of thermionicmeans'disclosed fas coniprisin'g "det'ector amplifier for balanced modula'tor tube ll so thataDqC. voltage appears across "the output resistors46and '46 of this j ube. The plate-cathodeoircuitof tubeil is'suppliedwith AxC. from transformer? by leads'82. The o ter -terminai62 of resistor 46'is connected fto terminal!!! and by *le'ads52 and 53 to one of f the horizontal deflecting plates, "whereas the "outer terminal 52 of resistor 46' is connected iead "'54 to "segment *A' of commutator 43. through contact" arm-'55'a'nd lea'd' 56 tot'he other iner-ment deflectingplate'fi. Thusthe-D. c. -"voltage "facr o ss' points 52 "and 62 ihorizontal'defiecting plates 4-5and "'45' 'and this voltage, together "with that across plates and TM", acts tos'o deflect the cathode ray beam' when- *evr aims 50 and "55 engage segments A as to pro uce-weep 1 of-Fig. lywhichspot moves around i'rr'a circular path' adjac'ent sc'a1e'=4 as the four'seoi "the-craft is changed" so that spot "1, whew'read upon scalel, serves t'o'indicatethe course of'the craft at any time.

"The"commutator'armsfland55are attached to appears "across similar to core 3| o. "e. 'voltage-applied to the vertieal defiectirig platesthroug'h commutator '42. This DfC. voltlongitudinal 'a'Xis "thereof and produce an-;a.-"c.

signal voltage thatis detected-and amplified and at plie'd throughthecommutator 42 to {the vertical "deflecting plates-in suoha way as "to-cause the horizon bar to tilt to simulate the tilting offthe'wings of the craft from the horizontal.

"Thus, the pick-ofi energizing coil 29 of the gyro horizoh is mounted on "a' five'lp'ole core 61 I and'fixe'd'to the gyrdhoriz on housin'g*65"as shownin Fig.4. Coils G3 ahd 6 3' on a pair'of' opposite poles of 'core "El are adapted "to turn with the craft "about "a'trans'verse axis thereof, 1. horizon. A spherical segment 'fi'l of magnetically e., the transverse axis of "the gyro "conducting materiar's carried by thegyrohoi izon rotor bearing casing or frame 68 concentrically with the rotor'axisthereof andis "positioned under "the poles'of core 6|,

theoz-inter of curvature ofthe 'spheric'alsurface of segment '51 intervals throughthe' action of arms "'5fl and- 55 andcorrimutators 42 and 43.

gyro or artificial horizon is also equipped *tvith two pairs of pick-off devices includingcoils, amer which pairs serves to producea' signal'depen'din g on-whether the nose of the planeis up or dowm and the other -of which'serves to show 'whethror not the wings are level. fixed A.'C. signal or voltage obtained from transformer or transformer means 26 is passed through commutatorfland applied to the horizontaldefiect- -ing pla'tes'45, 45 to -produce the straight horizon line'or' bar-B. This A. C. voltage is'supplied from the side of a'secondary of transformer 26 through orie'lead 64, segment D'of commutator 43,-ar-in 'and lead 56 to plate side of such'se'condary through the otherleadfifl, lead 52- and lead 53 to the plate" 45, thereby pro- --d ucing"line' 8.

"The bar or line"8fis-'mov'ed up or downas'the 45,' and from the other respect tothe other pair former 116, lead 64, lead 52 amplifiertube means are" supplied with. a D. C., i.

beingat'the point or intersectionof'the'giiflbal bearingstfi and ""69 of the gyro horizon. pole faces-of c'ore'fil lie inanimaginary-spherical surface having "the same center'of curvature-as the surface of segmental. The pitching of the craft shifts the segment with respect to 'c'oils'*63 and"63' toproduce asignal voltage of reversible phase ari'dvariablemagnitu'de that'is'supplie'd through a'ninput transformer T0 to the grids of' thermionic meansdis closed as comprising detecttar-amplifier orf modulator" tube 1 I, thereby producing across points 12 and 12 a variable magnitude, reversible D. C. voltag'ethat is "applied by lead "14 throughthe secondary of transformer (3, segment 'D, and a'rm5ll to'vertical deflecting plate""44 'of'tu'bet and by lead l5'through' the secondaryoftransand'lea'd '53'to the commompemt of plates'44"and45' and henceto Plat/e14. Thus, when the nose of the' craft rises and-falls, the bar or line'a, acted upon by D. C. potentials on plates 44 and derived'from tube 1|, is caused to be lowered or raised to simulatthe apparent motion of the horizon.

The roll of the craft shifts the segment 61 with of coils-l8 and I8';on core 6| to produce a signal voltage oi reversible phase and variable magnitude that'is supplied through transformer 19 to a thermionic push pull 80. The plates of tubes!!!) e., rectified'A. C. potential by means of tube also serving as a rectifier. This will be apparent when it is noted that-the plate-cathode circuit oftube-H issupplied with A. C. from transformer '26 through leads- 83 and that connected in this circuit isa filter consisting of condenser 84 and resistance 85-so that'the operation of tube ll causes a*D.C. potential to be supplied through lead 88 to -the center point of the primary winding of output transformer 16 and thence to the plates of tube beating of tube its'p1ate'potenti-a1 and grid bias.

degenerating network to eliminate'any motordue to possible variations in =-Thus-tube80 serves to supply an amplified verslon of the reversible phase, variable magnitude A. C. signal voltage supplied by coils l and 18' to the secondary of transformer 16. One side of the secondary of this transformer is connected through lead 15, point 12' to point I2, lead 14 through the secondary of transformer 13, segment D, arm 50 and lead to the vertical deto produce line 8, the addition of these voltages vectorially causes the horizon bar or line 8 to tilt in accordance with the tilting of the wings of the craft so that the line 8 gives all of the indications of the horizon bar of the gyro-horizon.

The vertical cathode beam line 9 (Fig. 1) is traced by-A. C. supplied from transformer means 25. A lead 9| supplies the potential at one point of a secondary of transformer 26 through segment B, arm 50 and lead 5| to one vertical deflecting plate 44, whereas the potential of another point of this transformer secondary is connected through lead 64, lead 52 and lead 53 to the other vertical deflecting plate 44', thereby causing the line 9 to be traced on the face of the tube 3. In order to cause the line 9 to shift or move from side to side corresponding to the turning of the plane, a suitable A. C, signal voltage is picked oil the turn indicator I9 and, after detection and amplification, is applied to the horizontal deflecting plates 45 and 45 as a D. C. control potential.

The turn indicator pick-off energizing coil 30 is mounted on a three pole core 93 (see Fig. 5) having its three poles arranged in a line With coil 30 on the center pole. Core 93 is fixed to the turn indicator housing 94. Coils 95 and 95' on the remaining poles of core 93 and coil 30 are inductively related to a cylindrical segment 96 of magnetically conducting material carried by the ring or rotor bearing frame 91 that is journaled for oscillation about a horizontal axis 98, the

rotor 99 being journaled for rotation on ring 91 on an axis extending at right angles to aXis 98.

The turning of the craft causes segment 90 to shift with respect to coils 95 and 95' to produce a signal voltage of reversible phase and variable magnitude that is supplied through an input transformer I00 to the grids of thermionic means disclosed as comprising detector-amplifler or modulator tube I 0|, thereby producing across points I02 and I02 a variable magnitude, reversible D. C. voltage. Point I02 is connected by lead I03 through segment B, arm 55 and lead 56 to one horizontal deflecting plate 45 of tube 3, whereas point I02 is connected through leads I5, 64, 52 and 53 to the other horizontal deflecting plate 45.

Thus, when the nose of the craft turns to the right or left, the vertical line or bar 9, acted upon by D. C. potentials on plates 45 and 45' derived from tube IOI, is caused to be moved to the right or left with respect to the central marking 6 to indicate the turn.

In case theair speed of the craft should fall below a predetermined safe minimum, the air speed indicator 24 or a Pitot tube actuated bellows is employed to close a pair of contacts I04 (see Fig. 2), thereby connecting leads 2! through a pair of leads I05 to a phase shift network I06, I01 supplying a transformer 13 havin one terminal of its secondary connected through lead 14, segment D, arm 50 and lead 5| to vertical deflecting plate 44, while its other terminal is connected through leads 14, I5, 64, 52 and 53 to plate 44, This out of phase voltage serves to distort the bar 8 into an ellipse such as shown at 8' in Fig. 6, thereby serving as a warning to the pilot to immediately increase the engine throttle opening. It will be apparent that instead of distorting the line 8 into an ellipse, the same may be distorted into other shapes by a properly applied out of phase voltage of the same or different frequency.

Sections C of the synchronously driven commutators 42 and 43 serve to switch the tube 3 to the radio course and landing beam circuits. A fixed voltage is obtained from transformer 26 and separated into two components apart, which, when applied to tube 3, produces the small circle II surrounding the black spot l0 (see Fig. 1) in the center of the screen. This circle II is moved horizontally by use of a D. C. voltage added in series with the horizontal deflecting plates to indicate departure of the craft from the radio beam. This D. C. voltage is the rectified output of the radio course beam receiver. The radio beam circle is moved vertically by means of a D. C. voltage added in series with the vertical deflecting plates to show departure of the craft from a radio glide landing beam. This D. C. voltage is obtained from the landing beam receiver output. Thus, to produce the circle II a lead I09 connects one end of a secondary of transformer 26 through a condenser IIO, section C, arm 55, and lead 56 to horizontal deflecting plate 45, while the other horizontal deflecting plate 45' is connected through lead 53, lead 52, lead 64, and lead III to the center tap of the secondary, thereby applying an A. C. potential to these plates in phase with the supply. An equal A. C. voltage shifted in phase 90", however, is provided by use of a condenser-resistance phase shift network II2 connected to the ends of the secondary winding, this voltage being supplied through lead H3, condenser I I4, section C, arm 50, lead 5| to one vertical deflecting plate 44, the other vertical deflecting plate 44 being connected through lead 53, lead 52, lead 54 and lead III to the center tap of the secondary. These 90 out of phase signal voltages by vector addition sweeping beam that describes the circle II.

When the craft departs laterally from the radio direction beam course, the reversing D. C. indications, normally fed to the zero center meter of the conventional course beam receiver 22 (Fig. l), are fed through the D. C. amplifier tube [I5 and added in series with the circle drawing voltage being fed the horizontal plate 45 of tube 3, thus deflecting the circle II from side to side, indicating the departure of the craft from the radio course. This addition voltage is applied across condenser H0 in lead I09. The plates of tube II5 are supplied from a secondary of transformer 25 through lead H6 and equal resistors II! and 7'.

Similarly, when the craft departs from the radio landing beam, the reversing D. C. indications normally fed to thezero center meter of the conventional radio landing beam receiver 23 (Fig. 1) are fed through the D. C. amplifier tube I I8 and added in series with the circle drawing voltage being fed the vertical plate 44 of tube 3, thus deflecting the circle II up and down, indicating the departure of the craft from the landing beam course. This addition voltage is applied across condenser H4. The p ates produce a transformer 26 through lead H3 and equal resistors I 2-II-and I20.

Figs. 6 to 8 show the indications of the instrument under varying operating conditions of the craft. Thus, in Fig. 6, the crafts course is 40, the ships nose is up as when climbing, and since the horizon bar 8 has opened up into an oval, the craft has fallen below the predetermined safe minimum air speed and hence is about to stall. The line 9 in central position shows that the craft is moving straight ahead and the circle II concentric with spot II) shows that the craft is on the radio beam course and radio landing beam course. In Fig. 7 the nose of the craft is down, the course is 130, the craft is moving straight ahead and is on both radio beams. In Fig. 8 the nose of the craft is up in making a climbing turn, the craft being oif both the radio course beam and the radio landing beam.

With the synchronous motor to driving the commutators 42 and 43, there would ordinarily be a back trace on the screen of tube 3, which back trace is drawn b the electron beam in its passage from one indication to the next. This back trace is annoying and is eliminated by cutting off the electron beam during the transition period. To do this, a commutator I22 is employed having its segments E respectively aligned with the gaps of commutators 42 and 43. Segments E are connected together and to the control grid of the cathode ray tube 3 by leads I23 and I24. Rotating arm I25 driven from motor 60 is connected to the ou end of potentiometer I26 by lead I21, so that when arm I25 engages one of the segments E it connects the tube control grid to the out end of potentiometer I26, thereby so increasing the negative bias on the tube grid that the cathode ray beam is momentarily shut off during each transition period. In Fig. 2 of the drawings, all heater connections have been omitted for the sake of simplicity, and the means for supplying filament, plate and focussing potentials for tube 3 have been grouped together in the box I30, since the same are entirely conventional.

In the event that the several instruments whose indications are portrayed by the instrument of this invention are located at a point remote from the pilots dash, such as in a box or cabinet at another point of the craft, then remote control means must be provided for caging and setting the directional gyroscope from the pilot's position. To accomplish this, the panel 2 is provided with the switch I5. When switch I is turned one notch from off position, it completes a circuit through leads I33 for a suitable motive means, such as a solenoid I3I (see Fig. 3), thereby causing this solenoid to move its core I32 to the right in Fig. 3 against the tension of spring I34 into the position shown in this figure. Such inward movement of the core I32 moves a gear I35 into mesh with a gear I36 on the base of the vertical ring 39. At the same time a conical recess I31 in gear 135 serves to centralize a pin I38, thereb raising a collar I39 and lifting pin I43 and locking arm I4I to effect the caging'of the gyro.

Switch I5 is now turned another notch, thereby completing a circuit through leads I42 to a motor I43, causing this motor to operate through gearing I44 to turn core I32 and gear I35, and hence gear I36, thereb turning the vertical ring and gyroscope in azimuth. The turning of the gyroscope will cause spot I to move around in acircular path adjacent scale 4 of the flight indicator on the pilot's dash, so that when the reading :of spot I on scale 4 corresponds to the reading of the magnetic compass, the pilot turns switch I5 off, thereby stopping the motor I42, deenergizing solenoid I3I and uncag-ing the gyro due to the action of spring I 34 in retracting gear I35. Patent #1,946,65'7 to Zand shows a manual caging and setting means using the mechanism shown within the lower part of housing 38.

"In the form of the invention shown in Fig, 9, electrostatic pick-01f or pick-on means from the directional gyro, the ro horizon, and the turn indicator are employed in lieu of the electro-magnetic pick-offs shown in the preceding figures, thereby minimizing the possibility of co- 1 ercion. Similar parts of Figs. 9 and 2 are simito input coils I48 and I48 in circuit with trimmer condensers I5I that are in turn connected to the grids of thermionic means disclosed as comprising a detector-amplifier or balanced modulator tube I49. A coupling coil I5!) is in ductivel related to coils I48 and I43 and is.

supplied with a high frequenc alternating current from an oscillator I51 through leads I52, the oscillator being supplied in turn from the transformer 26' energized from leads 25. Coil I50 induces current in coils I48 and I48 and the voltage across either of these coils may be varied at will by tuning them toward or away from resonance either by varying the capacity between condenser disc 36' and plates I46, I46" or by adjustment of the trimmer condensers I5I.

Preferably, the condensers I5I are so adjusted that when the capacity between disc '36 and plate I46 is equal to that between disc 36' and plate I46, then the voltage across each of the coils I48 and I46 is half Way down its resonance curve. Thus when disc 36' turns in response to the turning of the craft so as to cause disc 36 to cover a greater portion of plate I46, for example, and hence a lesser portion of plate I46, then coil I43 will be brought nearer to resonance while coil I48 will be turned further from resonance. to the upper grid of tube I49 will increase while that applied to the lower grid of this tube will decrease.

Alternating current of commercial frequency is supplied to the plate-cathode circuits of tube I43 through external leads I58 connected, preferably, to a, secondary (not'shown) of transformer 26. A resistor I53 connected between a lead I58 and the tube cathodes serves to bias tube I49 as a detector and, hence, as the voltages applied to the grids of tube I49 are oppositely varied, the plate currents drawn through output resistors I54 and I54 will be unequal, so that with the aid of smoothing condenser I55 a net D. C. voltage will appear across points I56 This 'D. C. voltage is applied through Hence, the voltage applied one vertical plate 44 of oscillograph 3, and through lead 53 to the other vertical plate 44' of tube-3 just as described in connection with Fig. 2 of the drawings. A bias filter condenser I59 is used in conjunction with bias resistor I53 and a blocking condenser I6!) is inserted between ground and the points of connection of condenser I59 and resistor I53.

Condenser plates I41 and I41 of the directional gyro are similarly connected to a detectoramplifier tube or thermionic means I6I, the output of which provides variable magnitude D. C. voltages across points I56 and I62. Point I62 is connected through lead 54, commutator 43, arm 55 and lead 56 to horizontal deflecting plate 45, whereas point I56 is connected through lead 53 to the other horizontal deflecting plate 45'. As the craft moves relative the directional gyro due to a change of course, the output voltages of the detector-amplifiers appearing across points I56, I56 and I62 are proportional to the deflection of the ship from course, and these voltages applied to the four deflecting plates of tube 3 act to deflect the beam by the vector sum of these voltage components, thereby producing the spot I (Fig. 1) which, when read on scale 4, accurately indicates the ships course just as i the previous form of the invention.

The gyro horizon is fitted with a condenser plate having the form of a grounded spherical segment 61' that cooperates with pairs of diametrically arranged segmental condenser plates I63, I63 and I64, I64, so carried by the gyro housing that as the craft pitches or rolls, opposite sets of plates are energized to unbalance the output of the amplifiers associated therewith. Thus, if plates I63, I63 are on a longitudinal axis of the craft, the pitching of the craft will cause these plates to be difierentially afiected and the output of the connected thermionic detector-amplifier I65 unbalanced, thus producing a D. C. voltage across points I66 and IE6, which voltage is communicated from point I66 through section D of commutator 42 to the vertical axis or plate 44 of oscillograph tube 3, and from point I66 through the secondaries of transformers I61 and I68 and leads I69 and 53 to the vertical plate 44'. Thus, this D. C. voltage applied to the vertical axis of the tube will raise and lower 'what- I ever indication is present on the horizontal axis. This indication is a straight transverse line produced by an A. C. voltage on horizontal deflecting plates 45 and 45' so that as the nose of the craft rises, the transverse line corresponding to the horizon falls, and vice versa. The A. C. voltage producing the artificial horizon line 8 (see Fig. 1) is sup lied from a secondary of transformer 26, one side of this secondary being connected through lead I16 and section D of commutator 43 to plate 45, the other side of the secondary being connected through leads I1I, I69 and 53 to the plate 45.

When the wings of the craft are tilted, plates I64 and W4 are differentially affected, thereby causing the plate circuits of thermionic detectoramplifier I12 to draw unequal currents through the equal halves of the primary of transformer I61, across which a condenser I13 is connected to bypass R. F. An A. C. voltage is thus produced in the secondary of transformer IE1, which voltage is connected to add in series with the D. C. voltage applied to the vertical axis of tube 3 from detector-amplifier I 65. This A. C. voltage is arranged to be directly in phase with the A. C,

lead 49, commutator 42, arm and lead 5| to voltage producing. the horizon line 6 and hence adds vectorially with the latter to produce a tilt in the horizon-line or bar proportional to the departure of the wings or transverse axis of th craft from the horizontal.

The electrostatic or capacity pick-off from the turn indicator is accomplished by use of a rounded semicircular condenser plate I14 attached to ring 91 on axis 98 (see Fig. 5) and cooperating with diametrically disposed segmental condenser plates I15, I15 carried by the gyro housing, which plates are connected as in the previous pick-off to the grids of thermionic detector-amplifier I16. As the turn indicator operates, tube I16 produces at points I11 and I11 variable magnitude, reversible D. C. voltages that are communicated from point I11 through lead I18 and commutator 43 to horizontal deflecting plate 45 and from point I11 through leads I69 and 53 to plate 45'. Thus, a D. C. voltage is present in the horizontal axis of the tube 3 which will deflect whatever image is being placed on the tube face by the vertical plates by an amount proportional to the rate of turn. The vertical axis of the tube 3 is synchronously supplied with an A. C. voltage from a secondary winding of transformer 26. This A. C. supply is by way of lead I19 through commutator 42 to vertical plate 44 and by way of leads I1I, I69 and 53 to vertical plate 44', thereby producing the vertical line 9, of Fig. 1. Hence line 9 will be deflected transversely in one direction or the other as the craft turns. When a turn is completed, the turn indicator will return to normal, the detectora'mplifier. I16 will be balanced so that no deflecting voltage is supplied to the horizontal axis of the tube 3, and the A. C. voltage across the vertical plates will return to its central position on the tube face or screen.

Means similar to that shown in Fig. 2 is provided for distorting the artificial horizon line or bar when the air speed falls below a predetermined Value. Thus, in Fig. 9, the bellow I connected to a Pitot tube is fitted with contacts I8I in circuit with an A. C. source, such as a secondary of transformer 26', and a phase shifting condenser and resistance combination or network I82, the out of phase output of which is fed through transformer I68 for application to the vertical plates of tubes 3 synchronously with the application of the remaining horizon bar voltages.

From the foregoing description it will be seen that I have provided a showing on the face of a cathode ray tube of indications of the attitude or orientation of the craft, about climb and bank axes, as furnished by the gyroscopic horizon, an indication of heading or orientation in azimuth from the directional gyroscope, an indication of direction and, rate of turn from a rate of turn gyroscope, and an air speed indication, all of which indications are actuated from instruments on the craft. In addition, I prefer to show on the same cathode ray tube an indication or indications of the position in space of the craft in azimuth and elevation with respect to a radio landing beam or beams.

To this end, means is provided in Fig. 9 for producin the small circle II surrounding the black spot I0 (see Fig. 1) in the center of the screen. This means is similar to that of Fig. 2 and hence will require but a brief description. The center tapof a secondary winding of transformer 26' is connected through leads I83, I1l,- I69 and 53 to the common of the horizontal and.

vertical deflecting plates of tube 3. An end of the secondary winding is connected through lead I84, in series with the output of the course beam receiver, lead I85, commutator 43 to the other horizontal plate 45, so that the horizontal plates are supplied with a fixed A. C. voltage equal to one half the output of the transformer secondary. At the same time the vertical plates of tube 3 are supplied with an A. C. voltage of equal magnitude but shifted in phase 90, this supply being through lead I86 in series with the output of the landing beam receiver, lead I81, potentiometer I88, lead I89 and commutator 42 to one vertical plate, and also through leads I83, I'II, I69 and 53 to the other vertical plate, thereby producing the circle I I.

If the craft departs from its course, the reversible D. C. output of the course beam receiver supplied through terminals I90 will cause the circle II to move transversely to indicate such ranged to supply the Department of Commerce bent beam, a different arrangement of voltage supply to the vertical axis of the indicator'tube 3 i necessary and such an arrangement is illustrated in Fig. 9. This bent type of beam is followed on a constant intensity basis and hence the rectified output of the landing beam receiver is shown supplied through terminals I'SI, potentiometer I88 and battery I91 to the vertical deflecting plates of tube 3. Potentiometer I88 is so adjusted as to place the radio circle II in the exact center of the screen when the output of the landing beam receiver is at its reference level. If the craft should then start to fly too high, for example, it will move nearer the center of the beam and the signal strength will increase, thus driving the circle I I downwardly on the screen of tube 3. On the other hand, should the craft start to fly too low, the received signal will decrease and the bucking voltage supplied by bat tery I91 through potentiometer I88 will drive the indicating circle I I upwardly.

Rectifier tube I93 and condenser I94 serve as rectifier and filter, respectively, for the plate and focussing potentials of tube 3. Leads 299 supply filament current to the cathode of tube 3. The control grid I95 of tube 3 is shown connected through resistor I96 to potentiometer I91. Adjustment of this potentiometer controls the brilliance of the cathode ray trace spot. Commutator I22 is also provided in this form of the invention and serves to increase the value of the negative potential applied to the control grid I95 at the instant when commutators 42 and 43 are switching from one indication to another. By this means the electron beam is cut off during commutation and the back trace, or unwanted lines connecting the several indications, is-eliminated. Focussing grid I98 is supplied with the proper potential and controlled from'potentiometer I99.

Although the novel flight indicator is shown as adapted to simultaneously portray the indications of some half dozen instruments, it is to be understood that the indications of a lesser or greater number of instruments may be so portrayed, if desired, by use of suitable pick-offs similar to those illustrated and by the proper detection, amplification and application of the desired voltages through the commutating means to the deflecting plates of the cathode ray tube 3.

As many changes could be made in the above .oonstruction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it 'is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It will be apparent that the cathode raytube may be provided with deflecting coils instead of deflecting plates, as is well known to those skilled in the art, an the expression deflecting plates" in thefollowing claims is to be understood as also covering deflecting coils.

What is claimed is:

1. In an aircraft flight indicator adapted to indicate the readings of a plurality of instruments on a single face, a plurality of instruments, electric pick-off means associated with said instruments for producing variable magnitude, reversible phase potentials in accordance with the indications of said instruments, means for supplying said pick-ofl means with A. C., thermionic detector-amplifiers for receiving the reversible phase and variable magnitude potential outputs of said pick-up means and for producing D. 0. output control potentials, a cathode ray tube, and commutator means for applying said D. C. control potentials in desired sequence to the deflecting plates of said tube.

2. In an aircraft indicator of the character described, a cathode ray tube having vertical and horizontal deflecting plates and a fluorescent face, means for intermittently applying an alternating potential to said vertical plates and for synchronously applying an alternating potential of the same magnitude but displaced 90 in phase to said horizontal plates to thereby produce a circle at the center of said fluorescent face, means for intermittently applying an alternating potential to said vertical plates to produce a straight vertical line at the center of said face, means for intermittently applying an alternating potential to said horizontal plates to produce a straight horizontal line at the center of said face, said straight lines intersecting one another and said circle at the center of said face, and means for applying additional potentials to said plates to cause said circle and lines to move over said face in accordance with theattitude of the aircraft.

3. An aircraft indicator as defined in claim 2, wherein means is provided to apply an out of phase A. C. potential to said vertical plates synchronously with the application of said horizontal line producing A. C. potentials to said horizontal plates when said craft falls below a predetermined air speed, whereby said straight horizontal line is distorted to indicate such loss in air speed. 1

4. In an aircraft indicator of the character described, an aircraft compass, electrical pick-oifs from said compass, on two mutually perpendicular axes, a cathode ray tube having vertical and horizontal deflecting plates and a fluorescent face, compass markings disposed around said face, and means connected to said pick-off for intermittently applying D. C. control potentials to said vertical plates and for synchronously applying D. C. control potentials to said horizontal plates, whereby a spot having an annular path of motion throughout 360 adjacent said cm-' pass markings is caused to appear on said face, said means being controlled so that said spot at any time, when read upon said compass markings, corresponds to the bearing of the aircraft.

5. An aircraft flight instrument, the combination with a radio receiver and an attitude indieating device showing both roll and pitch attitude, of a single instrument face, cathode ray means for indicating upon said face a plurality of separate aircraft indications, one of said indications having the appearance of a circle for indicating a radio beam path, and a second indication having the appearance of a horizon line for indicating both pitch and roll of the craft, said one indication being derived from said radio receiver and the second from said attitude indicating device, and means for independently moving said indications in accordance with the indications of said corresponding instruments.

6. An aircraft flight instrument, the combination with a radio receiver and a rate of turn indicating device, of a single cathode ray tube and means for indicating upon the face of said tube a plurality of separate aircraft indications, said indications being movable with respect to a common center on said face, one of said indications being derived from said radio receiver and another from said rate indicating device.

'7. In combination, a plurality of aircraft indicating instruments, electrical pick-off means associated with said instruments, a circular screen, means for projecting a luminous pattern on said screen constructed of elements normally symmetrical with respectto the center thereof, said elements corresponding respectively to and being distinctive of the indications of said several instruments, means for projecting said elements sequentially at a rate which causes them to be simultaneously and continuously visible, and means responsive to the potentials generated by said electrical pick-offs for causing said pattern elements individually or in combination to move in accordance with change of the indications of said instruments from their normal values, whereby said pattern is caused to become unsymmetrical with respect to the center of said screen. 8. In an aircraft flightindicator adapted to indicate the readings of a plurality of instruments on a single face, a plurality of instruments, electric pick-off means associated with said instruments for producing variable magniture reversible phase potentials in accordance" with the indications of said instruments, means for supplying said pick-off means with A. C., thermionic detector-amplifiers for receivin the reversible phase variable magnitude potential -outputs of said several pick-off means and for producing D. C. control potentials, a cathode ray tube having fixed markings on its face, commutator means for applying said D. C. control potentials in predetermined,sequence to the deflecting plates of said tube, means for applying A. C. potentials to said commutating means for application in predetermined sequence to the deflecting plates of said tube to produce continuously visible luminous markings on the face thereof corresponding to and distinctive of the indications of said instruments, and means for applying certain of said D. C. control potentials to change the position of said luminous markings with respect to said fixed markings.

,9. In an aircraft flight indicator adapted to indicate the readings of a plurality of instruments on a single face, a plurality of instru-.

ments, electric pick-off means associated with said instruments for producing variable magnitude reversible phase potentials in accordance with the indications of said instruments, an A. C. supply, means for excitin said pick-offs therefrom, thermionic detector-amplifiers for receiving the reversible phase variable magnitude potential outputs of said pick-off means and for producing D. C. control potentials therefrom, a cathode ray tubefcommutator means for applying said D. C. control potentials in desired sequence to the deflecting plates of said cathode ray tube, means for supplying A. C. potentials derived from said supply to the deflecting plates of said tube in proper phase relationships to cause distinctive markings to be traced on the face of said tube, and means for applying certain of said D. C. potentials to the deflecting plates of said tube to position said distinctive markings in accordance with the indications of said several instruments.

10. An aircraft flight instrument for simultaneously and continuously indicating rate of turn and attitude, comprising the combination with a rate of turn indicating device, an attitude indicatin device, a cathode ray tube, and common means for indicating upon the face of said tube a plurality of separate indications without interference therebetween, one of said indications being derived from said rate indicating device and another being derived from said attitude indicating device.

11. An aircraft flight instrument responsive to attitude sensitive devices providing as simultaneously and continuously visible luminous markings on the face of a cathode ray tube indications of the attitude of the aircraft with respect to three mutually perpendicular axes of rotation.

12. The combination with an aircraft horizon instrument having a horizon bar indicator and pick-off means on two mutually perpendicular axes, of a cathode ray tube, a pair of plates for deflecting the electron-beam thereof in a horizontal direction, a pair of plates for deflecting said beam in a Vertical direction, a source of A. 0., means for applying an A. C. potential derived from said source to said pair of horizontally directed deflecting plates to produce a luminous line on the face of said cathode ray tube representing the horizon bar of said horizon instrument, means for exciting said pickoifs from said A. C. source, means for deriving a variable magnitude, reversible polarity D. C. control potential from the output of the said pick-off on one of said axes, means for applying said D. C. potential to said vertically deflecting plates to position said horizontal line in accordance with the position of the horizon bar on said horizon instrument.

13. The combination with an aircraft horizon instrument having pick-offs on two mutually perpendicular axes thereof, of a cathode ray tube, a pair of plates for deflecting the electron beam thereof in a horizontal direction, a pair of plates plying an A. C. potential proportional to the out-' put of the said pick-01f on one of said axes to said vertically deflecting plates in phase with the potential applied to saidhorizontally deflectingplates, whereby said horizontal line is caused to tilt to a position determined by the vector sum of the potentials applied to said two pairs of defleeting plates.

14. An aircraft navigational instrument comprising in combination, a cathode ray tube having a circular face, means for causing the electron beam of said tube to trace a luminous circle normally concentric with the face of said tube, means for causing said circle to be displaced from its central position to the right or left in accordance with the departure of the craft from the center of a radio directional beam, means for causing said circle to be displaced from its central position upwardly or downwardly in accordance with the departure of the craft from the center of an inclined radio landing beam, means for causing said beam to trace a luminous straight line visible simultaneously with said circle, said line being normally substantially coincident with horizontal diameters of said tube face and of said concentric circle, thereby forming a distinctive pattern normally centralized on said face, and means responsive to change of attitude of the craft for displacing said line from said position of coincidence with said horizontal face diameter.

15. An aircraft navigational instrument comprising in combination, a cathode ray tube, an annular scale on the face thereof, means for causing the electron beam of said tube to produce a luminous spot as an index readable on said scale, means for positioning said spot relative to said scale in accordance with the course of the craft, means for causing the electron beam of said tube to trace a normally straight horizontal luminous line normally centered on the face of said tube, means for displacing said horizontal line upwardly or downwardly from its central position responsive to pitch of the craft, means for rotating said line from the horizontal responsive to roll of the craft, means for distorting said line when the air speed of the craft falls below a predetermined value, means for causing the electron beam of said tube to trace a normally vertical luminous line, normally centered on the face of said tube, means for displacing said vertical line to the right or left of its central position in accordance with the rate of turning of the craft, means for causing the electron beam of said tube to trace a luminous-circle normally concentric With the face of said tube, means for causing said circle to be displaced from its central position to the right or left in accordance with departure of the craft from the center of a radio directional beam, means for causing said circle to be displaced from its central position upwardly ordownwardly in accordance with the departure of the craft from the center of an inclined radio landing beam, and means for causing said several luminous markings to be flashed in rapid succession on the face of said tube, whereby the persistence of vision of an observer renders said markings simultaneously and continuously visible.

16. In combination, mounted on an aircraft, a plurality of aircraft flight instruments, means cooperating with said instruments for producing potentials corresponding to and varying with the indications of said instruments, and a single indicator for simultaneously and continuously indicating the information provided by all of said instruments on a single face, said indicatorcomprising a cathode ray tube having beamdeflecting means, and means .for successively applying said potentials in rapidly repeated sequences to said deflecting means for producing continuously visible luminous markings on the face of said tube, each movable in accordance with the indications of its respective instrument, distinctive markings being produced for simultaneously portraying on one face the information supplied by each of said several instruments.

17. In combination, mounted one; common aircraft, a plurality of aircraft instrume'nts'and-a single aircraft flight indicator for furnishing indications of said instrumenta'sid indicator comprising a cathode ray tube having beam deflectmg means, means for applying potentials inrapid succession to said deflecting means for causing the cathode ray beam .to produce continuously visible markings on the face of said tube corre'- sponding to and simulating the various movable indicating members of said instruments, indiyid ual electrical pick-off devices connected with said instruments sensitive to changes of indication thereof, individual electrical transmission circuits connected therewith, and'thermionicmeans con,- nected with said pick -ofi transmission circuits and responsive to the outputs of said-picl -ofis for* supplying control potentials to said deflecting nieans for actuating said markings in accordance 'th changes in the indications of said instruments.

combinatibn, QO 'e j ndii et ng air craft instrument, electrical pick-ofis on two tually perpendicular axes thereof, commutating means, thermionic amplifying and rectif n'g means for receiving the outputs of ,saldfieleet pick-offs and for producing D. C. ,control potentials for delivery to said commutating means, and a cathode ray tube having two pairsof deflec ng plates connected tosaid commutating,meanalsaid pairs being mutually perpendicular, whereby the control potential derived from one of said pickoifs due to operation of said instrument is successively and rapidly applied to ,one pair of said plates and the control potential derived from the other pick-off is similarly applied to the other pair of said plates, said intermittent operation occurring at arate which causes an'anparentlr continuous indication to be produced by cathode ray tube positioned on-the face thereof in accordance with thelffllative magnitudes of said two potentials. v

19. In an aircraft flight indicator'adapted to indicate the readings of a plurality of instruments on a single face, a pluralityof instruments, electrical pick-off meansassociated with each of said instruments for producing variable magnitude re.- versible phase potentials in accordance with the indications of said instruments, an A. C.;.sup ply, means for exciting, said pick-offs therefrom, thermionic detector amplifiers for receiving the re.- versible phase and variable magnitude potential outputs of said several pick-off means .and for producing D. .0. variable magnitude-reversible' polarity control potentials therefrom a cathode-ray tube, commutator means for applying one; of. ,Saiid D. C. control potentials and an A. C. potential proportional to 'theout'putof one ofsaid' pick iofls through saidcommutator means {one pairof deflecting plates, and meansfor applyingthe gap.- supply simultaneously through .said commutator means to otherplates of said tube.

20. An aircraft navigational instrument comprising in combination a cathode-raytube, means for causing the electron beam of ,S id tube-to trace a normally straight horizontal luminous line, means for causing said beam. to trace avertical line visible simultaneously withsaid'fiifst dicularly at the center of the face of said tube to form a cross, and means for altering said centralized cruciform pattern as to form and posiseveral indications thereof, a cathode ray tube,

means including a commutator for applying said D. C. potentials in rapid succession to deflecting plates of said tube, an A. 0. supply, means for supplying potentials derived from said supply to deflecting plates of saidtube in rapid succession through said commutator, and means for generating and applying through said commutator potentials to render said tube inoperative in the intervals between the application of said A. C. and D. C. deflecting potentials.

22. vAn aircraft navigational instrument as claimed in claim 20, having means for distorting said horizontal line responsive to loss of the critical air speed of the craft.

' 23'. In combination, aircraft instruments responsive to attitude, rate of turn and position of a craft relative to a radio beam, means for generating potentials responsive to the indications thereof, a circular screen, means for projecting a luminous pattern on said screen normally symmetrical with respect to the center thereof, said pattern including as elements an internal cross having vertical and horizontal limbs and an external circle concentric therewith, means for projecting said pattern elements sequentially at a rate which causes them to be simultaneously and continuously visible, means for displacing saidcross responsive to said attitude and rate of turn potentials, and means for displacing said circle responsive to said radio indication potentials whereby said pattern is caused to become unsymmetrical with respect 'to the center of said screen with changes of indication of said instruments.

24. As a navigational aid, mounted on a common aircraft, in combination, a, plurality of flight instruments indicating attitude of the craft and direction of flight, means for obtaining potentials proportional to the indications of said several instruments, a cathode ray tube having a beam controlling element and beam deflecting means, and A. C. supply, a plurality of segmental commutators, a beam controlling commutator having its segments aligned with gaps between segments of said first named commutators, said several commutators being synchronously driven by common means, means'for applying said instrument potentials and potentials derived from said supply to the deflecting means of said tube in desired sequence through at least one of said first named commutators to draw patterns on the face I of said tube distinctive of said several instruments and to move each of said patterns from a reference position, and means for applying potentials to the control element of said tube through said beam controlling commutator to prevent distortion of or undesired interconnection between said patterns. a

25. Apparatus mounted on an aircraft for aid= ing in piloting the craft comprising in combination, a plurality of instruments having electrical outputs altered by departure from normal flight conditions, a single cathode ray tube, means for applying potentials to said tube adapted to deflect the beam therein in a manner causing individually distinctive patterns to be traced on the face of said tube representative of said several instruments, commutating means for causing said several patterns to be flashed on said face in sufficiently rapid sequence to be simultaneously visible as distinctive indications, fixed indexes defining the normal positions of said patterns under normal flight conditions, said first named means including means for independently deflectingeach of said patterns from its normal position with respect to its index in accordance with and responsive to changes in the respective outputs of said instruments, whereby departure from a desired condition to which any of said instruments is sensitive is immediately indicated. 26. Apparatus mounted on an aircraft as a navigational aid comprising in combination, a plurality of instruments responsive to and having electrical outputs variable with departure from normal flight conditions, a single cathode ray tube, means for applying potentials to said tube to deflect the beam therein in a manner causing individually distinctive patterns to be traced on the face of said tube representative of said several instruments, commutating means for applying said potentials in rapidly repeated sequences to cause said patterns to be simultaneously visible,

said several patterns collectivel constituting an assembly formed and positioned under normal flight conditions for symmetry about horizontal and vertical lines passing through the center of the face of said tube, and means for causing the outputs of said instruments under abnormal flight conditions to displace said patterns and thereby destroy the symmetry of said assembly relative to said lines.

2'7. Apparatus mounted on an aircraft as a navigational aid comprising in combination a plurality of instruments responsive to flight conditions, a single cathode ray tube, and means for transferring the indications of said instruments to the face of said tube as simultaneously visible individually distinctive patterns, said means comprising means for deriving and app-lying to said tube control potentials suitable for tracing said to said cathode ray tube in rapidly repeated sequences for causing said patterns to be simultaneously visible and independently positionable.

28. Apparatus mounted on an aircraft as a navigational aid comprising in combination a plurality of instruments responsive to flight conditions, a single cathode ray tube, and means for transferring the indications of said instruments to the face of said tube as simultaneously visible individually distinctive patterns, said means comprising means for deriving and applying to said tubewontrol; potentials :lsuitables for L- tracings said p tterns, plck-offsmssociated witlr Saldi instrus l mlentsv each .of, said ;pick,-ofis inpludingsapair of; electrical circuits having; mt ntialss induced; therein by, ar -exciting source and means, for, dif+ ferentiallygvaryin said ;,inducedrpotentia1s.$m ac..-.. ordance itnthe 1 iIlG-l Qat F- -i tJthEA instrument ith whim; .l a id; pickwfiuaassociated; means fora- Obtaining from da nducedzpotentia s-.as ontrol;

potentiaysuitable for positioning on the face of said tube the pattern distinctive of the instrument with which said pick-off is associated, and commutating means for applying said several control potentials to said cathode ray tube in rapidly repeated sequences for causing said patterns to be simultaneously visible and independently positionable. I

29. In the guiding of an aircraft to a landing field, the method which comprises producing on the aircraft a plurality of visual images indica tive by their positions with respect to each other of the position and attitude of the aircraft, and substantially simultaneously controlling the positions of said plurality of visual images in accordance with energy radiated from the landing field and with energy developed on the aircraft to indicate the position of the aircraft with reference to a preselected approach path and the orientation of the aircraft with respect to a plurality of its axes.

30. In the radio-aided guiding of an aircraft carrying a gyroscopic device indicative ,of an orientation factor, the method which comprises producing on the aircraft a plurality of visual images indicative by their positions with respect to each other of the position and the orientation of the aircraft about a plurality of axes, and controlling the positions of said visual images in accordance with said gyroscopic device and with energy radiated from the landing field.

31. In the operation on an aircraft of guiding apparatus including an electronic tube having a screen and voltage-controlled means for producing images on the screen, the method which comprises forming first, second and third images on the tube screen, moving the first image vertically in accordance with the pitch of the aircraft and angularly in accordance with bank of the craft, moving the second image laterally in 'accordance with the turn or yaw of the aircraft, and moving the third image vertically and laterally in accordance with the location of the aircraft with respect to a preselected path of travel.

32. In apparatus for guiding an aircraft to a landing field, the combination with a cathode ray tube, and means for producing a plurality of visual images substantially simultaneously on the screen of said tube, of means responsive to energy radiated from the landing field for displacing at least one of said images vertically and laterally from a predetermined location to indicate the location in space of the aircraft with respect to a predetermined flight path, and means responsive to an attitude-indicating device on the aircraft for controlling the displacement of another of said images to indicate the orientation of the aircraft.

33. Guiding apparatus for use on aircraft comprising a cathode ray tube, means for producing a plurality of continuously visible images on the screen of the tube, means including a radiant energy receiver for displacing one of said images in accordance with the position of the aircraft with respect to a preselected course of flight, and means including a gyroscopic device for displacingranother image= =irr: aecordanceswith' \ti enattie tuderof. :the, aircraft;

34.= Guiding: apparatus aseclaimedcintclaimi33-gg whereintsaid la-st .imeanss. includes means aforrde-avelopinglaivoltageethat varies; with the pitch ofv'f thetaircraft;-.

35;; Guidinglapparatusrasrclaimed :in rclaimr33;

wherein- ;said: lastcmeansi includes ..=means forede-i,

veloping a voltage.rthatavarice;withzthesyaweof5 thew-aircraft,

36. Guiding apparatus for use on an aircraft comprising a cathode ray tube having vertical deflecting means and horizontal deflecting means, means including a receiver responsive to energy radiated from a landing field and a gyroscopic bank-and-climb indicator for producing a plurality of sets of control voltages proportional respectively to factors indicative of the position and the attitude of the aircraft, and commutating means for impressing said sets of control voltages in sequence on said deflecting means at a rate resulting in the production of a plurality of continuously visible images by the tube.

37. Guiding apparatus for use on aircraft comprising a cathode ray tube having vertical and horizontal deflecting means, means for impressing on said deflecting means control voltages proportional to the displacement of the aircraft from a preselected course of travel, means for impressing on said deflecting means a. control voltage proportional to the departure of the direction of travel of the aircraft from a preselected course, and means for impressing on said deflecting means control voltages proportional to the bank and the climb attitude of the aircraft.

38. In apparatus for guiding an aircraft having gyroscopic orientation indicating devices, means controlled by said devices for producing voltages varying with the orientation of the aircraft with respect to a plurality of its major axes, and means responsive to radiations emanated from a landingfield to produce voltages varying respectively with the vertical and the horizontal displacements of the aircraft from a preselected path of travel.

39. In the operation on an aircraft of guiding apparatus including an electronic tube having a screen and voltage-controlled means for producing images on the screen, a receiver responsive to radiant energy reaching the aircraft from a landing field, and an orientation indicating device; the method which comprises producing on the screen of the tube a plurality of continuously visible images, producing by said receiver and said indicating device control voltages that vary with the location and the orientation, respectively, of the aircraft, and controlling the position of each of the continuously visible images on the tube screen by said control voltages.

40. In the guiding of an aircraft to a landing field, the method which comprises producing on a fluorescent screen on the aircraft a plurality of continuously visible images indicative by their positions on the screen of the position and attitude of the aircraft in space, and controlling the positions of said images in accordance with energy radiated from the landing field and in accordance with energy developed on the aircraft, to indicate the position of the craft with respect to a predetermined approach path and the attitude of the craft with respect to a plurality of reference axes.

41. In the guiding of an aircraft carrying a gyroscopic device indicative of an orientation factor, the method which comprises producing on a fluorescent screen on the craft a plurality of continuously visible images indicative by their lodations on the screen of the position and orientation of the aircraft, and controlling the location of said images in accordance with said gyroscopic device and in accordance with energy radiated from the landing field.

42. In the operation on an aircraft of guid- 10 ing apparatus including a cathode ray tube, a receiver for crossed beams radiated from alanding field, and a gyroscopic device; the method which comprises producing on the cathode ray tube a plurality of continuously visible images, and selectively controlling the displacements of the several images in accordance with electrical voltages developed respectively by said receiver and by said gyroscopic device.

FRANCIS L. MOSELEY. 

